I just bought a 2003 Nissan Xterra. It has the 3.3L engine and after taking it in to a shop, reading the Haynes manual, and searching on line I am even more confused. Before purchasing the car I looked it over, crawled under, flicked every possible switch, and even hooked up my pocket scan. So it goes without saying that after purchasing it, and driving it for two hours the check engine light came on. I scanned again and the codes came back for catalytic converter failure(s). I took it in to the shop to see what they thought. Of course they said I needed to replace the catalytic converters, but I haven’t heard back from them. I have no problem doing the work myself but I can’t find answers for my questions. From what I can see the catalytic converters are “one piece” with the exhaust manifolds, with O2 sensors before and after. The problem is that 18" after those are two more canisters. The mechanic that checked the car says those are the actual cotalytic converters, but even if I change the (catalytic converters I may need to change the pre-catalytic convers. When I look up catalytic converters in the online parts, every site shows both.
If anyone can answer the following it would be greatly appreciated.
How many catalytic converters are there on this car?
Which are pre-cats, which are actual converters?
Are there aftermarket/performance systems that would meet the OBD2 requirements? (Magnaflow/Pace Setter/etc.) *Based on the over the phone quote from dealership I could replace the complete system with a performance system, but I am affraid to chage one problem for another.